. >>> the pentagon ordered its entire fleet of f-35 fighter jets grounded. here's why. a crack was found in the engine of one of the planes during a routine inspection. at nearly $400 billion, this high-tech jet system, this is for all of them, the most expensive weapon system in military history. $400 billion buys you 51 planes in that fleet. >>> a homework assignment has many up in arms. listen to this. two teachers at a new york elementary school wrote math word problems on slavery. here's one of the questions -- in a slave ship, there are 3,799 slaves. one day the slaves took over the ship. 1,897 slaves were dead. how many slaves are left? we could have done this with apples. the department of education says they will take disciplinary action against those teachers. training will also be required for all staff at the school. >>> the justice department says it plans to sue lance armstrong for using performance-enhancing drugs. they will join in the suit filed two years ago by former teammate floyd landis. the civil lawsuit claims that armstrong and his teammates viol